Electric rotating furnace



C. E. CORNELIUS.

ELECTRIC ROTATING FURNACE. APPLICATION FILED MAR. 27, 1920.

1,396,677, Patented Nov. 8, 1921.

2 SHEETS-SHEET I.

jvmweni'ar C. E. Cornelia/s. ,By x4553 C. E. CORNELIUS.

ELECTRIC ROTATING FURNACE. APPLICATION FILED MAR. 27, 1920.

, Patented Nov. 8, 1921 2 SHEETSSHEET 2.

Invevrfar 6'. Cornelius .present invention.

UNITED STATES CORNELIUS ERIK CQRNELIUS, OF STOCKHOEM, SWEDEN.

ELECTRIC ROTATING FURNACE.

Specification of Letters Patent.

Patented Nov. 8, 1921.

Application filed March 27, 1920. Serial No. 369,336.

To all whom it may concern Be it known that I, CORNELIUS ERIK CORNELIUS, a subject of the King of Sweden, and resident of 22 Narvavagen, Stockholm, in the Kingdom of Sweden, engineer, have invented certain new and useful Imp-rovements in Electric Rotating Furnaces, of which the following is a specification, reference being made to the accompanying drawings.

According to the invention of S. Huldt, U. S. Pat. 1,266,808, zinc powder when sufficiently heated and when simultaneously subjected to a rubbing action is turned over partly intoliquid zinc. The present invention relates to a method of melting zinc powder into liquid zinc and is characterized by the fact that the zinc powder is continuously fed into an electrically heated rotating furnace while the product, the so-called residue, which generally arises during the treatment of zinc powder and which chiefly consists of zinc'oxid and some metallic zinc, is continuously led away from or discharged from the furnace. By adjusting said discharge the whole process is made continuous and automatic, as the discharge regulates the introduction or feeding of the zinc powder into the furnace.

On the accompanying drawings are shown by way of example different forms of the Figures 1 and 2 show two sections, at right angles to one another, of one form of the invention, while Figs. 3 and 4 are similar views of the other form.

In both the cases shown the furnace itself consists-as is usual-of a cylindrical casing 1, surrounded by rings 2, which run on rotating rollers 3, whereby the casing or the furnace obtains its rotary motion.

The two rotating furnaces shown are principally intended for the continuous conversion of zinc dust into liquid zinc.

The zinc dust is fed down into a feeding funnel 4, the lower horizontal part 5 of which enters into a tube 6 fixed to the furnace 1 and thus rotating with it, this tube expanding conioally toward the furnace and forming a channel which passes into an opening 7 arranged centrally in one of the end walls of the furnace and thus coaxially with the axis of rotation of the furnace. The Zinc dust in the feeding funnel 4 falls by gravity into the tube 6, and passing through the latter enters into the furnace.

Another opening 8 is arranged in the other of the end walls of the furnace opposite to the opening 7 and in alinement therewith. The opening 8 communicates with a tube 9, which is fixed to, and thus rotates with, the furnace. At its outer end the tube 9 is provided with a. transverse wall 10, adjacent which apertures 11 are formed in the tube. The total area of these apertures is adjustable in one way or another.

It is to be understood in the operation of the furnace material which is fed into the.

same assumes a level substantially in alinement with the uppermost edges of the inlet and discharge openings 7 and 8 and inasmuch as the introduction of the material occurs by reason of gravity it is apparent that treatment of the zinc dust moves into thetube 9 toward the apertures 11, through which it escapes. By regulating the total area of the apertures 11 it is possible to regulate the escape of the residue, but as the supply of zinc dust according to that which escapes varies, said supply can also be regulated by adjusting the total area of the apertures 11. Both the supply of zinc dust to the furnace and the escape of the residue from it is thus continuous, automatic, and adjustable.

The liquid zinc obtained in the furnace which collects in the lower )part {10f the same, is tapped off through an outlet 12.

At the sides of the openings 7 and 8, electrodes 13 and 14 are fixed in the corresponding end walls of the furnace. The inner ends of these electrodes, which are diametrically opposed in relation to the axis of the furnace, are connected to a ringshaped resistance element 15, which may consist of carbon, carborundum or the like. The possibility of using a resistance of carbon is based on the fact that the glowing zinc dust is attacked, prior to the carbon. by any oxygen that might enter the furnace.

Owing to the heat generated inthe resistance by the electric current and as well In order that the resistance shall not come into contact with the liquid zinc, whereby irregularity in the supply of the electric current would result, the resistance is placed on a ring-shaped base 16'on the circular wall of the furnace.

For the supply of the electric current to the resistance 15 the-electrodes 13 and 14 are connected at their outer ends by means of wires 17 and 18 with contact rings 19 and 20, surrounding each of the tubes 6 and 9.

In the form of this invention which is shown in Figs. 3 and 4 the electrodes 13 and 14* are arranged in pairs, the electrodes of each pair being arranged in alinement with one another at the side of and around the axis of rotation of the furnace. Between each pair of electrodes there is a resistance 15 of suitable shape and nature.

In other respects this furnace isessentially similar to the one previously described.

If the zinc dust contains reduced lead powder, the latter is obtained in a molten .state together with the zinc.

In connection with the ring shaped'resistance element or band 15' and the resistance elements 15 it is tolbe understood that they serve in a capacity of agitators. Both are arranged circumferentially of and in spaced relation to the inner wall of thefurnace. The circumferential arrangement is apparent as regards the ring shaped or annular band, while the resistances 15* are arranged in a circumferential series as apparent from reference to Fig. 4. In view of the relative spacing of the elements 15 its is likewise apparent that they agitate the material.

The annular band serves as an agitator in a manner similar to the rubbing action occasioned by the rotating electric furnace. As the band is carried by and in spaced relation to the inner wall of the furnace it acts in a like manner for causing a secondary rubbing action or agitating of the material. Although the furnaces herein described have been stated as adapted for the converslon of zinc dust into liquid zinc, they, or other furnaces constructed in accordance with the present invention, may also be used forthe treatment of other material.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is: 1. The method of converting powder containing free metallic content into liquid state consisting in continuously introducing powder into a rotating heating device separately discharglng the free metallic content and continuously discharging the residues from said device.

2. The method of converting zinc powder lnto liquid zinc consisting in continuously char-ing the residues from said furnace,

nace, continuously discharging the residues from said furnace, and adjusting said discharge so as to automatically regulate the introduction of zinc powder into the furnace.

3. The method of converting zinc powder into a liquid state consisting in continuously introducing powder into a heated drum and continuously separating the free metallic content and continuously discharging the residue from'the device.

4. The method of converting zinc powder containing free metallic z'inc into a liquid state consisting in continuously introducing the powder into aheating device, then subjecting the powder to a rubbing action to separate and liquefy the metallic content and continuously discharging the residue from the device.

5. A method of converting powder containing free metallic zinc into a liquid state consisting in continuously introducing the powder into a rotating heating drum so as to subject the powder to a rubbing action to separate the free liquefied metallic content, and continuously discharging the residue from the drum.

6, The method of converting zinc powder containing free metallic zinc into a liquid state consisting in continuously introducing the powder into a rotating furnace, to subject the powder to a rubbing action to separate and liquefy the free metallic content, then agitating the powder and heating it to insure of the liquidation of practically all the free metallic content and simultaneously and continuously discharge the unliquefied residue from the-furnace.

7. In a rotating furnace for converting zinc powder into liquid zinc, means for continuously introducing the zinc powder into the furnace so that-it will be subjected to 'a rubbing action, means for continuously disi electric resistance means arranged circumferentially within and in spaced relation to the inner wall of the furnace to melt the zinc and to also agitate the material and facilitate the-melting action.

8. In a rotating furnace for converting zinc powder into liquid zinc, means for continuously introducing the zinc powder into the furnace so that it will be subjected to a rubbing action, means for continuously discharging the residues from said furnace, and an annular band arranged circumferentially within and in spaced relation to the inner wallof the furnace to melt the zinc and to also serve to agitate the material and thereby facilitate the melting action.

9. In a rotating furnace for converting zinc powder into liquid zinc, means for continuously introducing zinc powder into the furnace centrally of one sideso as to subject the material to a rubbing action and separate and melt the zinc, means for continuously discharging the residues from the furnace, and means for adjusting the discharge of the residues so as to automatically regulate the introduction of zinc powder into the furnace.

10. In a rotatin furnace for converting zinc powder into liquid zinc, means for introducing the zinc powder into the furnace, means for continuously discharging the residues from said furnace, an annular electric resistance element arranged circumferentially within the furnace and in spaced relation to the inner wall thereof for melting the zinc and for agitating the material to facilitate the melting action, and means for adjusting the discharge so as to automatically regulate the introduction of zinc powder into the furnace. V

In witness whereof I have hereunto set my hand in presence of two witnesses.

CORNELIUS ERIK CORNELIUS.

Witnesses:

H. B. OHLSSON, N. OHLSSON. 

